The production of oil fluids from an oil well normally moves through a life cycle to a point where the well lacks sufficient reservoir energy to lift the oil well fluid to the surface. When this occurs in a shallow well, the oil fluid may be lifted to the surface by conventional means, such as pumps or the like. In deeper wells it is necessary to increase the reservoir energy by pressurizing the formation with inputs of gas or water under pressure. The gas normally has to be a gas similar to that from the formation to eliminate oxygen and thus possible combustion of oil-gas fluids.
Even though the bottom hole pressure of the oil producing formation is sufficient to lift the oil fluids to a substantial height in the casing or tubing, or even to the surface, the well cannot be produced unless the oil fluids are moved out of the top of the tubing. The alternatives of providing gas or water drives through the formation for producing oil fluids are expensive and often times raise the economic limit of the well to a point where well production is ceased and the well is capped at a relatively early stage.
The problem of oil fluid drive is particularly complex in deep wells, where it is both difficult to use repressurizing by gas or water fluids or the like, and where the well is too deep to pump.
It is therefore advantageous to have a system for moving oil well fluids from the level that the oil producing formation raises the oil fluids in the casing or tubing, to the surface for production, and by means that is relatively inexpensive thus reducing the economic plugging limit of the well.